when one's back is turned(redirected from while back is turned)
when (one's) back is turned
When one is not looking; when one is distracted, absent, or involved in something else. Jimmy grabbed another cookie when his mom's back was turned. It turned out that the vice president of the company had been orchestrating a hostile takeover when the president's back was turned.
when one's back is turned
When one is away or not looking, as in You can count on the children to misbehave when the teacher's back is turned, or I don't dare go on vacation; he'll take my job when my back is turned. Also see when the cat's away, the mice will play.